Combined Use of Green Manure and Farmyard Manure Allows Better Nutrition of Organic Lettuce

Organic crop production has become a major business due to rising consumer demand, price premiums and increasing market opportunities. A field experiment was conducted to compare organic and conventional production systems by evaluating growth, yield and mineral content of lettuce leaves. Six organic productions systems, green manure (GM), farmyard manure (FYM), commercial organic fertilizer (COF) and their combinations were compared with conventional production system (CPS). A non-fertilized control treatment was also included. Plant growth and yield were found higher in the organic production system compare to conventional production system. The lowest plant growth and yield were obtained in the control treatment. Values of vitamin C content of lettuce grown in the organic production systems were higher than those of the conventional production system. The highest lettuce yield (71.8 and 76.5 t ha-1) was obtained with GM + FYM treatment. The results indicated that combined use of green manure and farmyard manure can be successfully used in organic lettuce production.